FDA certification of the Baltimore facility has now been delayed while inspectors investigate quality control issues and severely reduce the supply of Johnson & Johnson vaccines. The sudden drop in available doses sparked widespread complaints from governors and state health officials who had anticipated much larger deliveries of Johnson & Johnson’s vaccine this week than they did.
States have used the vaccine in a variety of settings, including at mass vaccination sites and on college campuses. The vaccine’s one-shot approach has proven popular, and officials have directed it to temporary, rural, and isolated communities where second-dose follow-up is more complicated.
It is common for regulators to investigate “safety signals” in new vaccines and other medical products. Very often the signals do not turn out to be critical. However, concerns about Johnson & Johnson’s vaccine echoes concerns about AstraZeneca’s vaccine, which European regulators investigated last month after some recipients developed blood clots.
Of 34 million people who received the vaccine in the UK, the European Union and three other countries, 222 had blood clots associated with low platelet levels. The majority of these cases occurred within the first 14 days after vaccination, mainly in women under 60 years of age.
On April 7, the European Medicines Agency, the main regulator, concluded that the disorder is a very rare side effect of the vaccine. Researchers in Germany and Norway published studies on April 9, suggesting that the AstraZeneca vaccine, on very rare occasions, caused people to make antibodies that activated their own platelets.
Still, regulators argued that the vaccine’s benefits – preventing infection with the coronavirus or preventing the few who get Covid-19 out of the hospital – far outweighed this small risk. Countries in Europe and elsewhere continued to distribute the vaccine to older people at high risk of serious illness and death from Covid-19, while restricting it in younger people.
Both AstraZeneca and Johnson & Johnson use the same platform for their vaccine, a virus known as adenovirus. On Tuesday, the Australian government announced that it would not buy Johnson & Johnson vaccines. They cited Johnson & Johnson’s use of an adenovirus. However, there is no obvious reason why adenovirus-based vaccines, in particular, would cause rare blood clots associated with low platelet counts.
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